Fixed .travis.yml escapes for sensitive configuration file generation

.travis.yml

@@ -18,7 +18,7 @@ install:
  - arduino --install-library "MD_DS3231"
 before_script:
  - sed -E "s/^#define ENABLE_(12H|DOW|DYNAMIC_CENTURY) 1/#define ENABLE_\1 0/" -i /usr/local/share/arduino/libraries/MD_DS3231/src/MD_DS3231.h # Disabling MD_DS3231 unwanted features
- - "tail --line=+`sed -n '/\/\/ #pragma once/=' src/config/User.h` src/config/User.h | sed 's/^\/\/ //' > src/config/Sensitive.h" # Using the example configuration file for compilation
+ - "tail --line=+`sed -n '/\\/\\/ #pragma once/=' src/config/User.h` src/config/User.h | sed 's/^\\/\\/ //' > src/config/Sensitive.h" # Using the example configuration file for compilation
 script:
  - arduino --verify --board arduino:avr:uno $PWD/src/GpsTracker.ino
 notifications: